Display device

Abstract

To suppress fluctuation in the threshold voltage of a transistor, to reduce the number of connections of a display panel and a driver IC, to achieve reduction in power consumption of a display device, and to achieve increase in size and high definition of the display device. A gate electrode of a transistor which easily deteriorates is connected to a wiring to which a high potential is supplied through a first switching transistor and a wiring to which a low potential is supplied through a second switching transistor; a clock signal is input to a gate electrode of the first switching transistor; and an inverted clock signal is input to a gate electrode of the second switching transistor. Thus, the high potential and the low potential are alternately applied to the gate electrode of the transistor which easily deteriorates.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a display device including a circuit formed by using a transistor. In particular, the present invention relates to a display device using an electro-optical element such as a liquid crystal element, a light-emitting element, or the like as a display medium, and an operating method thereof.[0003]2. Description of the Related Art[0004]In recent years, with the increase of large display devices such as liquid crystal televisions, display devices have been actively developed. In particular, a technique for forming a pixel circuit and a driver circuit including a shift register or the like (hereinafter also referred to as an internal circuit) over the same insulating substrate by using transistors formed of a non-crystalline semiconductor (hereinafter also referred to as amorphous silicon) has been actively developed, because the technique greatly contributes to low power consumption and low ...

AI Technical Summary

Benefits of technology

The present invention provides an industrially beneficial technique for controlling fluctuation in the threshold voltage of a transistor, reducing the number of connections between a driver IC and a display panel, reducing power consumption, and increasing the size and definition of a display device. The invention solves the problem of threshold voltage shift of a transistor by alternately applying a positive and negative power source to the gate electrode of the transistor. A switch is used to control the current flow through the transistor. The switch can be a transistor or a diode, and a CMOS switch can be used for more precise operation and reduced power consumption. The invention also reduces the number of wirings for controlling terminals and provides a more efficient solution for controlling fluctuation in the threshold voltage of a transistor.

Problems solved by technology

However, in the case where amorphous silicon is used for a semiconductor layer of the transistor, naturally, it becomes a problem in that a threshold voltage shift of a transistor which forms a circuit generating the AC pulse occurs.

That is, as problems which are not solved by the conventional technique, a problem of a circuit technique for controlling fluctuation in the threshold voltage of a transistor, a problem of a technique for reducing the number of connections of a driver IC mounted on a display panel, a problem of reduction in power consumption of a display device, and a problem of increase in size and high definition of a display device have been left.

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